If it has no mass, what stops it from going arbitrarily fast? Why doesn't it have infinite speed?
Permittivity & permeability properties determine e.m. wave speed.
Check out [post=1556816]this excellent post[/post] on the subject by rbj.⚛
Try writing down a wave equation where the speed of propagation is infinite :p
light is a special case .no mater what speed of light cannot be more than what it is.its a relativity concept.
Actually, it's not just light - as rbj points out in the post I linked to E&M, gravity, nuclear interactions, etc. all travel at the speed of light.⚛
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